java - 如何比较两个文件夹中的多个屏幕截图

Question

我正在尝试用 selenium 编写 java 代码来比较预期的屏幕截图和实际的屏幕截图。我创建了两个文件夹

• 屏幕截图
• IC截图

现在我正在尝试比较这些屏幕截图以确定它们是否匹配。这是我基本上重新搜索和编写的以下代码。尽管它正在从各个文件夹中读取文件，但比较失败。请指教 ？谢谢

public class ImageComparison {

    static String workingDir = System.getProperty("user.dir");  
    static String COMBINATION = "combine";
    static String SUBTRACTION = "subtraction";
    static String IMAGE_FILE_TYPE = "png";

    public static File listFilesForFolder(final File folder) {
        for (final File fileEntry : folder.listFiles()) {
            if (fileEntry.isDirectory()) {
                listFilesForFolder(fileEntry);
            } else {
                System.out.println(fileEntry.getName());
            }
        }
        return folder;


    }

    final static File folderActual = new File(workingDir+ "\\ICScreenshots\\");
    final static File folderExpected = new File(workingDir+ "\\Screenshots\\");
    static File fActual = listFilesForFolder(folderActual);
    static File fExpected = listFilesForFolder(folderExpected);


    public static void main(String[] args) throws IOException {

        BufferedImage imgA = ImageIO.read(new File(fActual + "." + IMAGE_FILE_TYPE));
        BufferedImage imgB = ImageIO.read(new File(fExpected + "." + IMAGE_FILE_TYPE));
        System.out.println(ImageComparison.bufferedImagesEqual(imgA, imgB));
        ImageComparison.subtractImages(imgA, imgB);
        ImageComparison.combineImages(imgA, imgB);
    }

    private static void combineImages(BufferedImage image1, BufferedImage image2) throws IOException {
        BufferedImage result = new BufferedImage(image1.getWidth(), image1.getHeight(), image1.getType());
        for (int x = 0; x < image1.getWidth(); x++)
            for (int y = 0; y < image1.getHeight(); y++) {
                result.setRGB(x, y, Math.abs(image2.getRGB(x, y) + image1.getRGB(x, y)));
            }
        ImageIO.write(result, IMAGE_FILE_TYPE, new File(COMBINATION + "." + IMAGE_FILE_TYPE));
    }

    private static void subtractImages(BufferedImage image1, BufferedImage image2) throws IOException {
        BufferedImage result = new BufferedImage(image1.getWidth(), image1.getHeight(), image1.getType());
        for (int x = 0; x < image1.getWidth(); x++)
            for (int y = 0; y < image1.getHeight(); y++) {
                result.setRGB(x, y, Math.abs(image2.getRGB(x, y) - image1.getRGB(x, y)));
            }
        ImageIO.write(result, IMAGE_FILE_TYPE, new File(SUBTRACTION + "." + IMAGE_FILE_TYPE));
    }

    private static boolean bufferedImagesEqual(BufferedImage img1, BufferedImage img2) {
        if (!(img1.getWidth() == img2.getWidth() && img1.getHeight() == img2.getHeight())) {
            return false;
        }
        for (int x = 0; x < img1.getWidth(); x++) {
            for (int y = 0; y < img1.getHeight(); y++) {
                if (img1.getRGB(x, y) != img2.getRGB(x, y))
                    return false;
            }
        }
        return true;
    }
}

我收到以下错误

Exception in thread "main" javax.imageio.IIOException: Can't read input file!
at javax.imageio.ImageIO.read(Unknown Source)
at fin.bi.test.ImageComparison.main(ImageComparison.java:36)

Answer 1

我假设您对编码有些陌生，因此我将列出不同的问题以及我为解决这些问题所做的工作，作为希望的教育练习。

1. listFilesForFolder()设置为向下导航到子文件夹，但您说您不需要它。它返回一个File但你说过你想循环所有文件。它还仅返回父文件夹(而不是实际文件)，这就是您收到错误的原因。您正在构建一个没有文件名的路径，因此它会抛出，因为预期的文件是一个文件夹。我重写了listFilesForFolder()返回 List<String>这样我们稍后就可以迭代它。

2. 您缺少循环浏览文件列表的代码。

3. 我更改了输出文件的名称以包含原始文件名。您的代码将重复写入现有文件减法.png。现在它输出一个文件，减法..png。

4. 我添加了一个参数，File outputFile , 至combineImages()和subtractImages()能够命名输出图像并避免覆盖输出文件。

假设文件夹结构

ICScreenshots\P1.png
ICScreenshots\P2.png
Screenshots\P1.png
Screenshots\P2.png
Screenshots\P3.png

其中 P1 相同而 P2 不同

输出看起来像

P1.png: true
P2.png: false
P3.png: does not exist in the ICScreenshots directory

代码如下

public class ImageComparison2
{

    static String workingDir = System.getProperty("user.dir");
    static String COMBINATION = "combination";
    static String SUBTRACTION = "subtraction";
    static String IMAGE_FILE_TYPE = "png";
    final static File folderActual = new File(workingDir + "\\ICScreenshots\\");
    final static File folderExpected = new File(workingDir + "\\Screenshots\\");

    public static List<String> listFilesForFolder(final File folder) throws IOException
    {
        List<String> files = new ArrayList<String>();
        try (Stream<Path> paths = Files.walk(folder.toPath()))
        {
            paths.filter(Files::isRegularFile).filter(path -> path.toString().endsWith(".png")).map(Path::getFileName)
                    .forEach(p -> files.add(p.toString()));
        }

        return files;
    }

    public static void main(String[] args) throws IOException
    {
        for (String s : listFilesForFolder(folderExpected))
        {
            File actualFile = new File(folderActual.getAbsolutePath() + "\\" + s);
            File expectedFile = new File(folderExpected.getAbsolutePath() + "\\" + s);
            if (actualFile.exists())
            {
                BufferedImage imgA = ImageIO.read(actualFile);
                BufferedImage imgB = ImageIO.read(expectedFile);
                boolean same = ImageComparison2.bufferedImagesEqual(imgA, imgB);
                System.out.println(s + ": " + same);
                if (!same)
                {
                    ImageComparison2.subtractImages(imgA, imgB, new File(COMBINATION + "." + s));
                    ImageComparison2.combineImages(imgA, imgB, new File(SUBTRACTION + "." + s));
                }
            }
            else
            {
                System.out.println(s + ": does not exist in the ICScreenshots directory");
            }
        }
    }

    private static void combineImages(BufferedImage image1, BufferedImage image2, File outputFile) throws IOException
    {
        BufferedImage result = new BufferedImage(image1.getWidth(), image1.getHeight(), image1.getType());
        for (int x = 0; x < image1.getWidth(); x++)
            for (int y = 0; y < image1.getHeight(); y++)
            {
                result.setRGB(x, y, Math.abs(image2.getRGB(x, y) + image1.getRGB(x, y)));
            }
        ImageIO.write(result, IMAGE_FILE_TYPE, outputFile);
    }

    private static void subtractImages(BufferedImage image1, BufferedImage image2, File outputFile) throws IOException
    {
        BufferedImage result = new BufferedImage(image1.getWidth(), image1.getHeight(), image1.getType());
        for (int x = 0; x < image1.getWidth(); x++)
            for (int y = 0; y < image1.getHeight(); y++)
            {
                result.setRGB(x, y, Math.abs(image2.getRGB(x, y) - image1.getRGB(x, y)));
            }
        ImageIO.write(result, IMAGE_FILE_TYPE, outputFile);
    }

    private static boolean bufferedImagesEqual(BufferedImage img1, BufferedImage img2)
    {
        if (!(img1.getWidth() == img2.getWidth() && img1.getHeight() == img2.getHeight()))
        {
            return false;
        }
        for (int x = 0; x < img1.getWidth(); x++)
        {
            for (int y = 0; y < img1.getHeight(); y++)
            {
                if (img1.getRGB(x, y) != img2.getRGB(x, y))
                    return false;
            }
        }
        return true;
    }
}